log -L: fix overlapping input ranges

The existing code was too defensive, and would trigger the assert in
range_set_append() if the user gave overlapping ranges.

The intent was always to define overlapping ranges as just the union
of all of them, as evidenced by the call to sort_and_merge_range_set().
(Which was already used, unlike what the comment said.)

Fix by splitting out the meat of range_set_append() to a new _unsafe()
function that lacks the paranoia.  sort_and_merge_range_set will fix
up the ranges, so we don't need the checks there.

Signed-off-by: Thomas Rast <trast@inf.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 10 insertions, 7 deletions

diff --git a/line-log.c b/line-log.c
index 5a12ceb012..85c7c249f4 100644
--- a/line-log.c
+++ b/line-log.c
@@ -56,16 +56,21 @@ static void range_set_move(struct range_set *dst, struct range_set *src)
 }
 
 /* tack on a _new_ range _at the end_ */
-static void range_set_append(struct range_set *rs, long a, long b)
+static void range_set_append_unsafe(struct range_set *rs, long a, long b)
 {
 	assert(a <= b);
-	assert(rs->nr == 0 || rs->ranges[rs->nr-1].end <= a);
 	range_set_grow(rs, 1);
 	rs->ranges[rs->nr].start = a;
 	rs->ranges[rs->nr].end = b;
 	rs->nr++;
 }
 
+static void range_set_append(struct range_set *rs, long a, long b)
+{
+	assert(rs->nr == 0 || rs->ranges[rs->nr-1].end <= a);
+	range_set_append_unsafe(rs, a, b);
+}
+
 static int range_cmp(const void *_r, const void *_s)
 {
 	const struct range *r = _r;
@@ -99,10 +104,8 @@ static void range_set_check_invariants(struct range_set *rs)
 }
 
 /*
- * Helper: In-place pass of sorting and merging the ranges in the
- * range set, to re-establish the invariants after another operation
- *
- * NEEDSWORK currently not needed
+ * In-place pass of sorting and merging the ranges in the range set,
+ * to establish the invariants when we get the ranges from the user
  */
 static void sort_and_merge_range_set(struct range_set *rs)
 {
@@ -280,7 +283,7 @@ static void line_log_data_insert(struct line_log_data **list,
 	struct line_log_data *p = search_line_log_data(*list, spec->path, &ip);
 
 	if (p) {
-		range_set_append(&p->ranges, begin, end);
+		range_set_append_unsafe(&p->ranges, begin, end);
 		sort_and_merge_range_set(&p->ranges);
 		free_filespec(spec);
 		return;